1. Field of Invention
The invention relates to an electrical connection clamp or terminal clamp for connecting an electrical conductor, with a clamp spring and with a metal part, the clamp spring having one clamp leg and one contact leg, in the clamp leg a recess for insertion of the electrical conductor which is to be connected being made, the clamp leg and the contact leg of the clamp spring being bent to one another such that the end of the clamp leg is inserted through a recess, on the end of the recess which is away from the end of the clamp leg a retaining section being punched out of the contact leg and being bent in the insertion direction of the electrical conductor which is to be connected, the metal part having a contact leg, an opposite retaining leg and a bridge which connects the legs, the end of the clamp leg of the clamp spring and the contact leg of the metal part forming a spring force terminal connection for the electrical conductor to be connected, and the ends of the legs each having an attachment section and the attachment section of the contact leg opposite the insertion direction of the electrical conductor to be connected extending through the recess.
2. Description of Related Art
German Patent Application DE 196 54 611 A1 and corresponding U.S. Pat. No. 5,975,940 discloses an electrical terminal clamp which has a U-shaped, open clamp spring and a conductor bar piece which is made as a corner angle. The conductor bar piece has a retaining leg which is located perpendicular to the conductor insertion, direction and a contact leg, in the retaining leg a rectangular opening being formed through which the electrical conductor to be connected can be inserted. The U-shaped clamp spring is inserted with the ends of its two legs in the opening and held such that the backward arc of the clamp spring in the conductor insertion direction is located in front of the opening and the clamp leg of the clamp spring presses an inserted electrical conductor against the contact leg so that the clamp spring and the conductor bar piece form a spring force terminal connection.
Similar electrical connection clamps with an essentially U-shaped clamp spring and a metal part are also known from German Utility Models DE 203 12 861 U1 and DE 202 10 105 U1. It is common to all these known connection clamps that the clamp spring with the ends of its two legs is inserted in an opening of the metal part so that when the clamp spring is opened there is the danger that the clamp spring will slip.
In addition, loop-shaped clamp springs for electrical connection clamps or terminal clamps are also known from the prior art, for example German Patent Application DE 197 11 051 A1 or German Patent DE 198 02 945 C2, specifically as so-called tension springs in tension spring clamps. Tension spring clamps have become established on the market over time in addition to screw clamps and are used in the millions, especially as terminal blocks. The advantage of tension spring clamps compared to screw clamps consists in that the tension spring clamps enable quicker and simpler wiring. For actuating the tension spring clamp only one actuating tool is needed, for example a screwdriver, which is inserted into an actuating shaft to open the clamp. In doing so, the tip of the screwdriver tensions the tension spring, by which the clamp site is opened. A conductor which is to be connected can be inserted through the recess in the clamp leg. After removing the screwdriver, the conductor is pulled by the lower edge of the recess against a conductor bar which is connected to the tension spring and thus makes electrical contact.
The known tension spring clamps however clearly differ in their configuration and in their function from the initially described connection clamp or terminal clamp. In the known loop-shaped tension springs, corresponding to their name, the conductor to be connected is pulled by the clamp leg against the conductor bar. In contrast, in the above described connection clamps or terminal clamps the conductor to be connected is pressed by the clamp leg against a region of the metal part.
The initially described electrical connection clamp or terminal clamp underlying the invention is known from German Patent Application DE 10 2004 046 471 B3. In this known connection clamp, the clamp spring however is not made U-shaped—as in the terminal clamp known from German Patent Application DE 196 54 611 A 1—but loop-shaped, in the contact leg of the clamp spring which is located not parallel, but essentially perpendicular to the insertion direction of the electrical conductor to be connected, there being a recess for inserting an electrical conductor which is to be connected. The clamp leg and the contact leg of the clamp spring are bent to one another such that the end of the clamp leg is inserted through the recess.
In the known connection clamp or terminal clamp, the fixing of the clamp spring and metal part takes place by the clamp spring with its recess being slipped onto the metal part. To attach the clamp spring relative to the metal part, for this purpose, two attachment sections are provided on the metal part, both of which are inserted through the recess opposite the insertion direction of the electrical conductor to be connected. To mount the clamp spring on the metal part, thus, the contact leg with its recess is inserted over the two attachment sections of the metal part so that the recess extends around the two attachment sections in the manner of a frame. In addition, on the end of the recess away from the end of the clamp leg, a retaining section is punched out of the contact leg of the clamp spring and is bent essentially perpendicular to the contact leg and extends behind the attachment section of the retaining leg from the outside.
But, for this terminal clamp, there is also the danger of the clamp spring being detached or lifted off from the metal part. This danger exists especially when the clamp spring is actuated, i.e., when a conductor is inserted into the clamp site or when the clamp spring is opened since the clamp spring can tilt so that only the attachment section of the contact leg extends through the recess. The danger that it slips when the clamp spring is being opened prevails especially when the clamp spring is not held in its position by the housing which surrounds it.